This invention is directed to floating structures and, more particularly, to floating structures formed of concrete.
As will be better understood from the following description of the invention, the term "floating concrete structure(s)", as used herein, is to be given a broad construction. It encompasses movable structures suitable for use in transporting gasses, liquids, semi-solids and the like. In addition, it includes relatively stationary structures, such as docks, floating platforms, buoys and the like.
The use of concrete to form floating structures, such as boats, platforms and the like has been proposed in the past. However, for various reasons, the utilization of concrete for this purpose has not found widespread acceptance. On the other hand, concrete has a number of advantages which make it a desirable material for such uses. For examples, concrete is long lasting, and it "ages" well when left in sea water; that is, the structural strength of concrete improves with age, even when left permanently in sea water. Further, concrete is not readily attacked by acids and other corrosive materials contained, for example, in crude oil.
Therefore, it is a general object of this invention to provide new and improved concrete structures suitable for use in water.
On the negative side, in the past, it has been necessary for floating concrete structures to have relatively thick walls in order for such structures to have adequate strength. One of the major reasons for this requirement is inability of concrete to flex. More specifically, iron, wood and fiberglass have some flex or elasticity. Thus, when these materials are used to form the hull of a floating structure, such as a boat, some of the energy of the waves impinging on the side of the structure is absorbed by the structure flexing, as opposed to being absorbed by the strength of the structure per se. On the other hand, comparitively, concrete is relatively inelastic. Hence, in order for a concrete boat to have the overall structural strength of an iron or steel boat, the hull walls must be relatively thick. Because they are relatively thick, they are undesirably heavy. Because they are undesirably heavy a large portion of the energy driving the boat is required just to move the hull of the boat. Thus, the driving energy is not efficiently utilized to move the cargo carried by the boat. Obviously, it is desirable to provide a concrete boat that makes use of inexpensive concrete; yet does not possess these disadvantages of prior art concrete boats.
Therefore, it is a further object of this invention to provide a new and improved floating concrete structure suitable for use as a boat.
It is a further object of this invention to provide a new and improved concrete boat suitable for transporting materials at sea.
At the present time, relatively large ocean vessels are utilized to transport products, such as crude oil, liquified natural gas, and refined gasoline products (herein referred to as oil products) and the like, from the source of the product to the market for the product. Modern "oil" tankers are formed of iron hulls and have capacities up to 400,000 dead weight tons (d.w.t.), and tankers having capacities up to 800,000 d.w.t. have been proposed. There are two major problems associated with iron hull oil tankers of this nature. These problems are related to the oil tankers regardless of their size; however, they are magnified by the larger tankers presently plying the sea lanes, and those proposed. Specifically, these problems relate to pollution of the oceans and the surrounding shoreline.
Oil pollution generally occurs in either of two ways. The most publicized way occurs when a tanker is severely damaged by, for examples, collision with another boat or running aground. When such a tragic event occurs, an extremely large amount of oil rapidly enters the surrounding water, polluting it and, often, the adjacent shoreline.
The second major cause of sea pollution occurs when ballast water is pumped overboard prior to oil loading. Specifically, during the return from a market to a source of oil products, an oil tanker must carry ballast water. Ballast water is carried in the same compartments or container where oil is carried during the trip between the source of the oil products and the market. Thus, residual oil products become mixed with the ballast water, i.e., the ballast water becomes contaminated. When the tanker nears the source of the oil products, the ballast water is removed, often by pumping it overboard into the ocean. Because the ballast water is contaminated, it contaminates the surrounding ocean.
While proposals have been made to solve the foregoing problems, the proposed solutions are relatively expensive. For example, expensive electronic equipment has been developed to assist in the navigation of ships so that the possibility of collision and groundings can be reduced. In addition, expensive facilities have been provided to store ballast water on land and "clean" it prior to its being returned to the sea. In addition, ballast water cleaning systems have been included on board relatively large tankers to clean ballast water prior to its being pumped overboard. As indicated above, all of these solutions have one thing in common--they are expensive. Obviously it would be desirable to prevent large oil spills, and the initial contamination of the ballast water, whereby it would not have to be decontaminated.
Therefore, it is also an object of this invention to provide a floating structure for transporting oil products and the like that does not release an extremely large amount of such products into the surrounding sea even if severely damaged.
It is another object of this invention to provide a floating concrete structure suitable for carrying oil products and the like wherein ballast water is not comingled with oil products.
As alluded to above, the basic structure of the invention is not only useable to transport products at sea, it is also useable in other environments, herein generally referred to as floating platforms. In this regard, as used herein, the term "floating platform(s)" includes buoys, relatively large platforms such as floating bridges, helicopter landing pads, artificial deep sea ports, etc. In addition, the term floating platform(s) includes relatively small platforms suitable for use by marinas to form docks, floating gas stations and the like.
In the past, one of the major disadvantages of using concrete to form floating platforms has been the requirement that some form of floating support structure, such as logs, metal drums and the like, be utilized to support a pad made of concrete. Because the prior art requires subsidiary elements, such as metal drums, wood logs and the like, which deteriorate over relatively short periods of time, when kept in contact with sea water, the long lasting benefits of concrete are lost.
Therefore, it is another object of this invention to provide floating platforms essentially entirely formed of concrete.
It is yet a further object of this invention to provide concrete floating platforms suitable for use in the sea to form docks, floating bridges, buoys and other similar structures.